HP B6960-90078 manual Locking Devices Used Exclusively by Data Protector

Configuring and Using Backup Devices

Shared Devices in the SAN Environment

Using FC-AL SANs Using tape devices in Fibre Channel Arbitrated Loops (FC-ALs) may

with LIPcause certain anomalies that could abort a backup session. This problem arises because the FC-AL performs a Loop Initialization Protocol (LIP) whenever a new FC link is connected or disconnected, or whenever a system connected to the FC-AL is rebooted. This re-initialization of the FC-AL causes running backups to be aborted. Such terminated jobs should be restarted.

When a LIP occurs on the FC-AL Loop, any utility with an active I/O process shows an I/O error. For backup utilities attempting to use a shared tape, an I/O error causes failure of the current backup session, causing active tapes to be rewound and unloaded, and the backup session to abort.

To avoid these problems, take the following precautions:

•Do not add new devices or remove devices from the Arbitrated Loop while backup sessions are running.

•Do not touch FC components while backup sessions are running. The static charge can cause a LIP.

•Do not use discovery on Windows or ioscan on HP-UX system since these also cause a LIP.

Locking Devices Used Exclusively by Data Protector

If Data Protector is the only application that uses a drive, but that same drive needs to be used by several systems, Device Locking has to be used.

If Data Protector is the only application that uses a robotics control from several systems, Data Protector handles this internally, provided that the library control is in the same cell as all the systems that need to control it. In such a case, all synchronization of access to the device is managed by Data Protector internal control.

Locking Devices Used by Multiple Applications

If Data Protector and at least one other application want to use the same device from several systems, the same (generic) device locking mechanism has to be used by each application. This mechanism needs to work across several applications. This mode is not currently supported by Data Protector. Should this be required, operational rules must ensure exclusive access to all devices from only one application at a time.

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